Let's just face the facts, shall we (even BTC fans/bagholders)
BTC transfers are nerve wreckingly slow.
BTC transfers are disgustingly expensive.
BTC is at the mercy of chinese gigamines.
BTC experiences sudden enormous swings that appear out of the blue.
And every time BTC does "its thang", the altcoins move with it, since BTC is the most widely used base currency at crypto exchanges. This causes unnecessary stress for people who own coins that actually work as a means of payment or have some other intrinsic value.
BTC is a big old lazy animal, its only virtues are being the first and, consecuently, having no 1 market cap now. But that is changing. Just look at the BTC dominance number on Coinmarketcap. Used to be over 60% not too long ago, now it's 34%. And when BTC loses its no 1 status, what follows then? Likely a collapse, that could bring the whole crypto market down. We need to untie well functioning coins from this dinosaur so it wouldn't bring the whole crypto market down when it decides to die.
We have heard several of this reason and even more of than what you listed here but still the top is reserved for bitcoin and despite all the challenges you listed there none is not surmountable and with various option to adopt by users, its a thing of the past.
Now to adoption of a coin as a base currency, if you have an option you can say it but of all the coins we have only ETH can stand and to a large extent there it has been given its own recognition. Decisions like that are not taken based on impulse or in a hurry just because such coin is in the face of attention or has the right technology and the price is increasing not at all its based on how acceptable, how easy it can be converted to fiat, the test of time it has spent etc. Without that, I am sorry, you are stuck with btc.